[ec.cen.tric.i.ty] n, pl -ties (1545) 1 a: the quality or state of being eccentric b: deviation from an established pattern or norm; esp: odd or whimsical behavior
2. a: a mathematical constant that for a given conic section is the ratio of the distances from any point of the conic section to a focus and the corresponding directrix b: the eccentricity of an astronomical orbit used as a measure of its deviation from circularity